feat(review): grant the claude reviewer child a read-only tool allowlist

Headless claude -p auto-denies any tool call that would have prompted interactively, and buildReviewCmd passed no permission config — so finder subagents bounced off denials for git diff/log/show and detoured around them (observed in a live review transcript: 'attempted tool calls, hit approval/tool restrictions, and continued').

Pass --allowedTools with the read-only surface a review needs: Read/ Grep/Glob/Task/TodoWrite, enumerated read-only git subcommands (not Bash(git:*) — aliases/hooks execute arbitrary code and push/commit match the blanket), and entire's read-only lookup commands referenced by the checkpoint context. Never --dangerously-skip-permissions: reviewers process untrusted diffs and must stay unable to write.